PLEASE HELP! I apologize for the long description but this problem is beginning to negatively impact my fiancee and my health and from what i have read, withholding rent from your landlord is thin ice to walk on if your not positive.

My fiancee and i have lived in our apartment for almost 2 years now. During this time the building has been sold to 3 separate companies. We have filed maintenance requests with each company for the same problems. The problems which persist are:

1-Our apartment has 6 windows, only 2 of which have the storm windows/screens which help insulate and keep bugs out. Each owner has sent maintenance up to measure for replacements (current owner sent one roughly 3 months ago) but none of them have actually replaced the storm windows/screens.

2-When we were shown the apartment the stove, dishwasher and refrigerator had not been installed but we were assured they were installing new appliances. We ended up receiving all the appliances from a second hand store (the landlord left the stores "used appliance" sticker on them). The dishwasher was filled with mold, which we cleaned on our own dime, and it does not really wash our dishes as it does spread the food around. That appliance is not as bad as the fridge which has been leaking from the freezer into the lower half, soaking and, in some cases, ruining food and/or creating mold. Again maintenance was up to look at it roughly 3 months ago but has done nothing about it.

3-We used to have cockroaches which, after 3 exterminations, were finally removed...only to be replaced with bed bugs. Our landlord has sent an exterminator out 4 times now for this problem. The problem got so bad after the first extermination my fiancee and i stopped sleeping in our bedroom and began sleeping on a blowup mattress in our living room. After the 4th extermination, the exterminator told us the bugs had been gone from our bedroom for a long time and told us to move back in. The next morning i awoke covered in bedbug bites and proceeded to kill 2x-3x the amount we had normally seen. I contacted our landlord and told her the extermination company they were using was not doing the job and requested a new company be used, to which she replied "Sir, we dont bring these bugs into our buildings, so..." which i took as "Its your problem, YOU deal with it." I explained to her prior to our infestation we had received notice tenants were improperly disposing of mattresses and furniture, then everyone else on this floor moved out within a month. I have also explained to her in the past we do not fit any of the criteria of bringing bed bugs into the building (ie travel, pets, improperly disposed diapers, etc.) The landlord then told me she would call her supervisor and call me back. That was almost a week ago. My fiancee and i are both beginning to experience negative health effects due to the bed bugs, including severe itching, loss of sleep and open sores on our arms and legs. I have read that under Massachusetts law i can hire my own exterminator and deduct the cost from my rent, up to 3 months.

Everything i have listed (and more) has been explained to our landlords thoroughly. I have been investigating my options and my next step was to write a formal request for the repairs and pest removal to be done correctly within a week or i will withhold my rent. Then shop around and hire a company better suited to deal with bed bugs and deduct the cost of their fees from my rent. Is this the right route to take? Is there a better route? or am I completely in the wrong? At this point all i want is to get rid of the bugs, the other 2 problems are so minor in comparison i only intend to use them as backing/leverage.